The invention relates to bearing arrangements, and, more particularly, to bearing arrangements for reducing friction between the connecting rod and the crankpin of an internal combustion engine.
Such bearing arrangements, which typically include roller bearings located between the crankpin and the connecting rod, sometimes cause crankpin spalling. Spalling occurs because the load from the connecting rod is most highly concentrated on the uppermost bearing, i.e., the bearing closest to the piston. This load concentration is repeatedly transmitted to the crankpin, and the cyclical stress on the crankpin results in spalling of the crankpin.
Spalling can occur either on the outside of the crankpin (caused by combustion loading when the piston is in the top dead center position) or on the inside of the crankpin (caused by inertia loading when the piston is in the bottom dead center position). Spalling on the inside of the crankpin due to inertia loading is most common in modern, high rpm engines.
Attention is directed to the following U.S. patents:
______________________________________ Underwood 2,914,367 Nov. 24, 1959 DeHart, et al. 3,625,580 Dec. 7, 1971 Sihon 3,789,743 Feb. 5, 1974 McKindree 3,801,173 Apr. 2, 1974 Yahraus 4,073,550 Feb. 14, 1978 Matzelle 4,383,719 May 17, 1983 Roberts 4,311,349 Jan. 19, 1982 Mahrus, et al. 4,461,585 Jul. 24, 1984 Thompson 4,488,826 Dec. 18, 1984 ______________________________________